Evaluating the scope of intramedullary invasion of malignant bone tumor by DCE-MRI quantitative parameters in animal study.

UNLABELLED

The purpose was to analyze the value of quantitative parameters of DCE-MRI in evaluating micro-infiltration of malignant bone tumors.

METHODS

Thirty-nine New Zealand white rabbits were used to establish malignant bone tumor models by implanting VX2 tumor fragments into the right tibiae. After three weeks, models were examined by conventional MRI and DCE-MRI; then the right tibiae were cut into sagittal sections and partitioned into histology slices for comparison with microscopic findings. Micro-infiltration groups were selected and the range of infiltration was determined under the microscope, and corresponding DCE images analyzed to obtain the quantitative parameters include and in parenchyma areas, micro-infiltration areas and simple edema areas. One-way ANOVA was used to compare the differences of the parameters between the three areas. Receiver operating characteristic curves (ROCs) were plotted to determine the accuracy of different parameters by area under curves (AUCs).

RESULTS

22 cases (22/39, 56.4%) were included in the micro-infiltration group and the infiltration depth ranged from 1.3 mm to 4.6 mm, with an average depth of 3.2 mm ± 0.8 mm. The statistical results of quantitative parameters in the three areas were as follows: values were (0.494 ± 0.052), (0.403  ±  0.049), (0.173 ± 0.047) min ( = =0.000), values were (1.959 ± 0.65), (1.528 ± 0.372), (1.174 ± 0.486) min ( = =0.000), values were (0.247 ± 0.068), (0.283 ± 0.057), (0.168 ± 0.062) min ( = =0.000), values were (0.125 ± 0.036), (0.108 ± 0.033), (0.098 ± 0.025) min ( = =0.022), respectively. and values had significant difference in the three areas after comparing between-groups, respectively. However, there were no significant difference in values between parenchyma and micro-infiltration areas ( = =0.078), micro-infiltration and simple edema areas ( = =0.315), and values between parenchyma and micro-infiltration areas ( = =0.056). The values were higher in parenchyma and micro-infiltration areas then simple edema areas. had highest accuracy in differentiating different areas (AUC > 0.9), respectively.

CONCLUSION

Quantitative parameters and can assess the extent of intramedullary invasion of malignant bone tumors. have highest accuracy in differentiating different regions.